Kothbauer Karl F
*Department of Neurosurgery, Luzerner Kantonsspital, Luzern, Switzerland; and †University of Basel, Basel, Switzerland.
J Clin Neurophysiol. 2017 Jan;34(1):32-37. doi: 10.1097/WNP.0000000000000314.
To provide a summary of the intraoperative monitoring of muscle motor evoked potentials (MEPs) based on the presence-absence concept during neurosurgical operations along the spinal cord.
Expert review.
The measurable parameters of MEPs, such as signal amplitudes and thresholds vary considerably both during a single surgery in a single individual patient as well as between individuals and operations. The presence or absence of responses irrespective of stimulus intensity and response amplitude is much more clearly defined. The correlation of intraoperative MEP data to clinical findings preoperatively and postoperatively so far is best if a presence-absence paradigm is used. The most reliable correlation of postoperative motor deficits is with the disappearance of previously present MEPs, not with the deterioration of amplitudes or the elevation of thresholds. However, in intraoperative decision making an elevation of threshold, without signal loss may still be considered a practical warning sign as it may be a subclinical injury indicator, and may therefore induce a change in surgical strategy. This may be considered a minor warning criterion. A practical concept of the combined use of MEPs with D-wave recordings produced a neurophysiological pattern, which correlates with a reversible motor deficit: Disappearance of MEPs correlates with transient motor deficits if the D-wave amplitude is preserved above an approximate value of 50% of its baseline. Disappearance of the D-wave correlates to paraplegia.
To date, the best correlation of muscle MEP data to clinical deficits lies in the assessment of disappearance of a previously present MEP regardless of thresholds or amplitudes. Increase in stimulus thresholds for MEPs or to a lesser degree decrement of signal amplitudes may be considered subclinical injury indicators without correlation to neurological dysfunction and thus is considered a minor warning criterion.
总结基于有无概念的术中肌肉运动诱发电位（MEP）监测在脊髓神经外科手术中的应用。
专家综述。
MEP的可测量参数，如信号幅度和阈值，在单个患者的单次手术过程中以及个体和手术之间差异很大。无论刺激强度和反应幅度如何，反应的有无都更明确。如果使用有无范式，术中MEP数据与术前和术后临床结果的相关性迄今为止是最好的。术后运动功能障碍最可靠的相关性在于先前存在的MEP消失，而不是幅度的恶化或阈值的升高。然而，在术中决策时，阈值升高而无信号丢失仍可被视为一个实际的警示信号，因为它可能是亚临床损伤指标，因此可能导致手术策略的改变。这可被视为一个次要的警示标准。MEP与D波记录联合使用的一个实用概念产生了一种神经生理模式，它与可逆性运动功能障碍相关：如果D波幅度保持在其基线近似值的50%以上，MEP消失与短暂性运动功能障碍相关。D波消失与截瘫相关。
迄今为止，肌肉MEP数据与临床功能障碍的最佳相关性在于评估先前存在的MEP的消失，而不考虑阈值或幅度。MEP刺激阈值的增加或信号幅度较小程度的降低可被视为亚临床损伤指标，与神经功能障碍无关，因此被视为一个次要的警示标准。
